Babies born prematurely frequently lack the ability to keep their lungs from collapsing. Under normal circumstances, a baby's lungs will expand during inhalation and only partially contract during exhalation. Premature or newborn babies frequently have weak inspiratory movements causing collapse of the lung after exhalation. Collapse may also occur in the newborn as a result of blockage of bronchioles by mucus or from failure of the lung to distend.
For adults, lung collapse is a condition which may result from a lowering of intrapulmonic pressure or an increase in intrathoracic pressure. It may be focal, involving only a few lobules, or massive, in which an entire lobe or the complete lung is involved. It may result from obstruction of the bronchial tubes (obstructive atelectasis) or pressure upon the lung by air or fluid in the pleural cavity, an intrathoracic tumor, or a greatly enlarged heart (compressive atelectasis). Air may be introduced artificially into the pleural cavity (artificial pneumothorax) or it may be derived from emphysematous lesions.
The following patents reflect the state of the art of which applicant is aware and is included herewith to discharge applicant's acknowledged duty to disclose known prior art. It is stipulated, however, that neither patent teaches nor renders obvious when considered in any conceivable combination the nexus of the instant invention as disclosed in greater detail hereinafter and as particularly claimed.
______________________________________ U.S. Pat. No. ISSUE DATE INVENTOR ______________________________________ 4,261,355 April 14, 1981 Glazener 5,193,532 Moa, et al. ______________________________________
For example, the patent to Glazener teaches the use of a constant positive pressure breathing apparatus in which a cylindrical channel, serving as a conduit for gases either spontaneously or mechanically aspirated by a patient includes in said channel a narrow diameter nozzle venting compressed gas in the direction of inspired flow.
Moa, et al. teaches the use of a device for generating continuous positive airway pressure in which a fresh gas inlet channel admits gas into a breathing channel such that the fresh gas channel terminates substantially flush with the breathing channel.